Potential benefits of using cardiac gated images to reduce the dose to the left anterior descending coronary during radiotherapy of left breast and internal mammary nodes.

PURPOSE: To assess the benefits of using cardiac gated images for treatment planning of breast and internal mammary nodes. PATIENTS AND METHODS: Inspiration breath hold computed tomography (CT) series acquired at prospectively gated diastolic phase were used for planning. Three different techniques were compared. Technique A used tangents and an internal mammary nodes field covering the three first inter-rib spaces; technique B used an extended internal mammary nodes including part of the medial breast in junction with tangential fields; the 3(rd) technique used helical tomotherapy. For each technique, two treatment plans were performed: one plan (plan-01) where mean dose and V(25) to the heart were considered for plan evaluation and a second plan (plan-02) where the irradiation of the left anterior descending artery was minimized. RESULTS: V(25) to the heart was found to be less than 5% for all six plans. Mean doses to the heart were within 4.8 to 7.2 Gy. By attempting to lower the dose to the left anterior descending artery, heart D(mean) was decreased by 20-30% for the two techniques A and B while being unchanged for tomotherapy. Regarding target coverage, there was no marked difference between plans where only heart dose was considered (plans-01) and plans where the left anterior descending artery dose was minimized (plans-02). When the left anterior descending artery dose was part of plan evaluation, D(mean) to the left anterior descending artery could be decreased by 24, 19 and 9% for techniques A, B and tomotherapy respectively. The three techniques exposed segments of the left coronary to different levels of dose. CONCLUSION: This study showed that evaluation of the dose to the left anterior descending artery coronary may change the treatment strategy. Cardiac gated images without IV contrast permitted a good visualization of the coronaries in order to optimize the dose on these structures. In addition to heart V(25,) the dose to the coronaries should be included in prospective studies on radiotherapy related heart toxicity in association with all additional risk factors.

Tratamento hipofracionado de radioterapia em felinos portadores de carcinoma epidermóide facial / Hypofractionated radiation therapy for the treatment of feline facial squamous cell carcinoma

Avaliou-se a eficácia do protocolo radioterápico hipofracionado no tratamento de felinos portadores de carcinoma epidermóide facial. Um protocolo hipofracionado de radioterapia foi aplicado em cinco gatos portadores de um ou mais carcinomas epidermóides faciais, em um total de 10 lesões neoplásicas, confirmadas por meio de análise histológica. Duas lesões foram classificadas como T1, quatro como T2, duas como T3 e duas como T4. Os animais foram submetidos a quatro frações radioterápicas de 7,6 a 10gy, com intervalo de uma semana entre elas, utilizando-se um acelerador linear com feixe de elétrons. O acompanhamento dos animais foi realizado semanalmente durante o tratamento e aos 30 e 60 dias após o término da radioterapia. Neste estudo, 40 por cento das lesões resultaram em remissão completa, 40 por cento em remissão parcial e 20 por cento não apresentaram resposta ao tratamento. A taxa de resposta encontrada nessa pesquisa foi baixa, porém o protocolo de hipofracionamento radioterápico foi seguro para gatos com carcinoma epidermóide facial e resultou em efeitos colaterais leves/moderados.

The efficacy of hypofractionated radiation protocol for feline facial squamous cell carcinoma was evaluated. Hypofractionated radiation therapy was applied to five cats showing single or multiple facial squamous cell carcinomas, in a total of ten histologically confirmed neoplastic lesions. Of the lesions, two were staged as T1, four as T2, two as T3, and two as T4. The animals were submitted to four radiation fractions from 7.6 to 10 grays each, with one week intervals. The equipment was a linear accelerator with electrons beam. The cats were evaluated weekly during the treatment and 30 and 60 days after the end of the radiation therapy. In this study, 40 percent of the lesions had complete remission, 40 percent partial remission, and 20 percent did not respond to the treatment. Response rates were lower as compared to other protocols previously used. However, hypofractionated radiation protocol was considered safe for feline facial squamous cell carcinoma.

Prospective randomized trial comparing hyperfractionated versus conventional radiotherapy in stages III and IV oropharyngeal carcinoma.

From April 1986 to May 1989, 112 patients seen at a single institution with previously untreated squamous cell oropharynx carcinoma, Stages III and IV, were randomly assigned to 66 Gy in 33 fractions of 2 Gy each (conventional RT) versus 70.4 Gy in 64 fractions of 1.1 Gy given twice a day with a minimal interfraction interval of 6 hours (hyperfractionated RT). The overall time for both arms was 6 1/2 weeks. Patients were stratified by site (base of the tongue vs others), T stage (T1/T2 vs T3 vs T4), N stage (N0/N1 vs N2 vs N3), and lymphnode size (less than 6 cm vs greater than 6 cm). As of January 1990, an analysis was performed in 98 patients (8 patients in the conventional arm and 6 in the hyperfractionation not included). The groups were balanced by age, performance status, stage, and site of the primary disease. The median follow-up time was 25 months. The probability of complete loco-regional response was 62% in the hyperfractionation arm and 52% for the conventional fractionation (p = 0.28). There was no difference in the control of lymphnodal disease (hyperfractionated = 55%, conventional = 57%; p = 0.92), but the disease control in the oropharynx only was significantly improved in the hyperfractionation arm (84% vs 64%, p = 0.02). Overall survival rate at 42 months was 27% for the hyperfractionation arm and 8% for the conventional (p = 0.03). Survival rates for hyperfractionated versus conventional RT were 40% versus 18% (p = 0.06), respectively, for Stage III patients and 16% versus 0% (p = 0.15), respectively, for Stage IV. There was significant improvement in survival in favor of the hyperfractionation arm in patients with lesions outside the base of the tongue (31% vs 15%, p = 0.02), for those with a 50-70% Karnofsky status (19% vs 0%, p = 0.006) and for patients with N0/N1 disease (38% vs 15%, p = 0.03). Acute toxicities were of similar magnitude, although both skin and mucosal reactions appeared earlier on the hyperfractionation scheme. To date, no differences in late toxicity have been observed. We conclude that in a subset group of patients with locally advanced carcinoma of the oropharynx, hyperfractionated radiotherapy appears to provide improved survival without adding to increased toxicity.

A randomized trial of chemotherapy followed by pelvic radiation therapy in stage IIIB carcinoma of the cervix.

Because of the poor results in stage III B carcinoma of the cervix with standard treatment using radiotherapy alone, we designed a randomized trial to determine whether administration of chemotherapy before pelvic irradiation would improve survival. Between May 1984 and August 1986, 107 patients with previously untreated squamous cell carcinoma were randomly assigned, after stratification by age (less than 50 v greater than 50 years), extent of parametrial involvement (unilateral v bilateral), and lymphangiographic findings (negative v positive) to pelvic radiotherapy (RT; arm A) or three cycles of chemotherapy (CT; bleomycin, vincristine, mitomycin, and cisplatin [BOMP]), followed by the same radiotherapy regimen (CT + RT; arm B). The groups were balanced by age, performance status, extent of parametrial involvement, bulkiness of cervical disease, nodal involvement, and presence of hydronephrosis. Minimal follow-up is 34 months. A complete local response was observed in 32.5% of the patients in arm A and in 47% of the patients in arm B (P = .19). Overall 5-year survival rates were 39% for the RT arm and 23% for the CT + RT approach (P = .02). Toxicity was severe in arm B and included fatal pulmonary toxicity in four patients. Locoregional and distant failures were similar in both groups. We conclude that, despite a satisfactory response rate, neoadjuvant BOMP chemotherapy adversely affects survival in stage III B cervical cancer and is associated with unacceptable toxicity.

A randomized trial comparing radiation therapy versus concomitant radiation therapy and chemotherapy in carcinoma of the thoracic esophagus.

From September 1982 to December 1985, 59 previously untreated patients with Stage II squamous cell carcinoma of the thoracic esophagus were randomly assigned to receive radiation therapy (RT) alone versus the concomitant use of RT and chemotherapy (CT) with 5-fluorouracil (5-FU), mitomycin C, and bleomycin (RT + CT). Thirty-one patients were randomized to the RT regimen and 28 to the RT + CT regimen. The complete local response rate was 58% for the RT group and 75% for the RT + CT group (P = 0.77). The median duration of response was 8 months for both groups. The overall 5-year survival rates were 6% and 16% (P = 0.16) for the RT and RT + CT groups, respectively. Acute toxicities were more pronounced in the RT + CT group. This clinical trial did not detect a difference in outcome with combined-technique therapy. This result must be interpreted with caution because of the small number of patients entered in this trial. Confirmation of the value or lack of value for combined therapy will require additional larger clinical trials.